v3.25.4

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2025 | Dec. 31, 2024
Development fees | $ 1,903 | $ 3,003
Vornado |  |
Development fees | $ 34 | $ 346

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- Definition Non-cash additions to real estate included in accounts payable and accrued expenses. + References No definition available. + Details
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Namespace Prefix: | alx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |